How to make a racing lawn mower (Updated!)

Step 19 Finishing up and final adjustments.

Final Adjustments

With all of the sheetmetal painted the mower was fully assembled. Pretty nice looking if I don't mind saying so. Now there was only one thing left to do- which was to race it and see what it would do. The first race was actually what we call our "Test-n-tune" day where all the new "mowchines" are brought out and tested... and tuned up.

 Mine had some serious handling problems. The mower was pushing into the corners. It was so bad that I could barely stay on the track. As it turned out my steering system was wayyyyyy out of whack. To fix this I did some serious adjusting. This involved doing a few things:

1: adjusting the front right wheel so that it had more camber. As it turned out I had somehow welded the right spindle mount on at the wrong angle. Luckily all I had to do was simply thread the top heim joint inward until the camber was corrected. The right wheel was also dropped downward a bit. This enabled the right front to push down onto the front left.

2: Adjust the toe-out. As mentioned before, toe-out means how much the wheels splay outwards- as in they turn away from the mower a bit. It doesn't take much. Only 1/8" on each side. Doesn't sound like much but this will greatly help the mower become far more stable.

 The first "real" race we had was a huge difference. The mower did much better. That said, there are still some issues. The biggest is that I chose not to install a high performance cam. This would greatly help with low end torque and faster acceleration out of the corners. This is relatively simple to do and only involves removing the bottom of the engine. I'll decide on what to do about this soon.

 In the meantime if you want to see the mower racing in action, check out our racing group's web site which is chok-full of videos.
www.pvmowerracing.com

 Thanks for reading and stay tuned for even more updates!